Prosthetic attachment locking devices are used to secure a residual limb, which has been fitted in a socket, to a pylon of a prosthetic limb. The prosthetic attachment locking device generally includes a body having an axial hole extending therethrough and a locking mechanism having a spring loaded reciprocating pawl that cooperates with the axial hole. The socket has a socket adapter that is attached to a first surface of the body by a fastening means that is passed through a set of through-holes in the body. An attachment pin that extends from a liner positioned about the residual limb is inserted through the socket adapter and through the axial hole of the prosthetic attachment locking device until a distal end of the attachment pin is received in the pylon of the prosthetic limb. As the attachment pin is inserted, ratcheted teeth of the attachment pin engage with teeth of the pawl. Because the pawl rotates in only one direction, the attachment pin becomes locked in the body and secures the residual limb to the prosthetic limb. To release the attachment pin from the body, the pawl is displaced from the axial hole so that the pawl disengages from the attachment pin. The attachment pin is then removed from the body to unsecure the residual and prosthetic limbs.
Because many prosthetic attachment locking devices use either a one-way clutch or a ratchet to limit the rotation of the pawl to a single direction, if the attachment pin reaches a point of complete insertion in-between locking positions, a certain amount of play can occur between the pawl and the attachment pin. Additionally, the ratcheted teeth of the attachment pin are generally rounded and do not completely mesh with the teeth of the pawl, which can cause a certain amount of play to occur between the ratcheted teeth of the attachment pin and the teeth of the pawl. Because any type of play that occurs between the attachment pin and the pawl causes the prosthetic limb to move in relation to the residual limb during use, a user may experience discomfort and/or the attachment pin may become loosened from its locked position within the body. Further, the body receiving surface of the socket adapter is often irregular as a result of grinding during the fabrication process. The irregular body receiving surface can cause further discomfort to the user.